The art is generally cognizant of blinds having slats adapted to transmit at least some of the light that impinges on them. Curtis, Jr., U.S. Pat. No. 2,633,191, discloses a tiltable horizontally slatted venetian blind of very sturdy construction for use as a fireplace screen, but which is also suggested for use over windows. Friedman, U.S. Pat. No. 2,620,869, discloses a venetian blind slat construction in which the slats are made of plastic materials. Malone, U.S. Pat. No. 3,645,317 shows a conventional Venetian blind in which the slats are covered with a thin layer of metal to reflect unwanted infrared radiation and yet remain generally transparent to visible light. In the closed position, the slats of Malone overlap, doubling the light-blocking effect of the blind.
The art is also cognizant of blinds that have a selected color on one face and a second color on the other face. An example is Schaller, U.S. Pat. No. 4,336,834.
The use of blind slats bent along their longitudinal axis so as to acquire a cross sectional configuration similar to an inverted V is also known. Examples include Berlad, et al., U.S. Pat. No. 4,091,592, Renton, U.S. Pat. No. 2,318,525, and Ehrenfeld, U.S. Pat. No. 2,315,605. Thompson, et al., U.S. Pat. No. 3,217,631, shows a similar configuration employed as a fixed louver. In each case, the bent slat is opaque and is adapted not to be turned about its longitudinal axis. The purpose of the bent configuration of the slats is to block light or provide privacy while allowing a substantial flow of air.